The bike we obtain from that side mission is waterproof. The purpose of going fast is to fall underneath the map closest to the second island so we spawn over there. Same with third island.
@TheBTA yes that's what I meant if the trick works with the respective weapon and of its not too much to ask for can you make a guide on where all those motorcycle missions are?
Out of the three missions in the game I've showcased two (9mm Mayhem and AWOL Angel) Scooter Shooter is in north east Chinatown. Here's a guide www.gtabase.com/gta-liberty-city-stories/side-missions/drive-by-missions
